Discovery of Self-Assembled Nanoparticles from Rubia cordifolia L. Before and After Carbonization and Mechanistic Study on Their Targeted Therapy for Ulcerative Colitis

This study reveals for the first time that madder can drive natural components to self assemble and form structurally superior nanoparticles (PRCL NPs) through charcoal frying, providing a scientific explanation of the "charcoal storage" theory at the nanoscale. • Compared with RCL NPs, PRCL NPs have smaller particle size (∼400 nm), higher stability, and exhibit excellent colitis targeting and macrophage uptake ability after processing. • PRCL NPs are significantly more effective than raw products in treating ulcerative colitis (UC) models, effectively alleviating colitis symptoms and promoting tissue repair. • Through multi omics integration analysis, it was first elucidated that PRCL NPs exert synergistic anti-inflammatory effects by activating the IL-17A/IL-22-C/EBP β - STAT3 signaling axis and inhibiting the expression of downstream key chemokines (CCL5, CXCL5, CXCL10). Background Ulcerative colitis (UC) is a chronic inflammatory bowel disease with limited treatment options. The carbonization of Rubia cordifolia L. traditionally enhances its therapeutic effects, but the mechanism remains unclear. Objective To investigate whether carbonization induces self‑assembled nanoparticles (PRCL NPs) from Rubia cordifolia and to elucidate their mechanism in UC. Study design Self‑assembled nanoparticles were extracted from raw (RCL NPs) and carbonized (PRCL NPs) Rubia cordifolia. A DSS‑induced acute UC mouse model was used to evaluate efficacy. Transcriptomics, proteomics, Western blot, and ELISA were performed to explore the mechanism. Methods Nanoparticles were characterized by DLS, SEM, FTIR, and stability assays. DSS‑induced colitis mice were orally treated with RCL NPs or PRCL NPs (1.3 and 5.2 g/kg). Inflammatory and pathway markers were assessed. Results PRCL NPs exhibited smaller particle size (337.2 nm vs. 947.2 nm) and enhanced stability (zeta potential –15.2 mV). Multi‑omics revealed convergent enrichment of the IL‑17 signaling pathway. PRCL NPs significantly upregulated IL‑17A, IL‑22, p‑STAT3, and p‑C/EBPβ (p < 0.001) and suppressed chemokines CCL5, CXCL5, and CXCL10. Conclusion Carbonization of Rubia cordifolia spontaneously forms structurally optimized self‑assembled nanoparticles (PRCL NPs) that alleviate UC by modulating the IL‑17A/IL‑22–C/EBPβ–STAT3 axis. This study provides a modern nanoscale interpretation of traditional processing theory. Download: Download high-res image (241KB) Download: Download full-size image